NUMBERS AND MEASURES. 



13. 



Greek. 



A pous 1-01 foot. 



Olympic stadium 60675 feet. 



A metretes 16'46 gallons. 



A medimnus 18*61 gallons. 



Persian and Asiatic Greek talent 71*65 Ibs. 



Attic commercial talent 64'65 Ibs. 



Euboic and Attic monetary talent ( = 6000 drachmae) 56 '22 Ibs. 



Roman. 



A pes -97 foot. 



A passus ( 5 pedes) (a mile 1000 passus) 4 '8 5 5 feet. 



A jugerum | acre ? 



An amphora (== 8 congii 3 modii) 5725 gallons. 



An as or libra (= 12 uncise) 7165 Ibs. 



(15) THE ACCELERATION DUE TO GRAVITY. 



The apparent acceleration, or rate of increase of velocity per 

 second, of a body falling freely in vacua under the action of gravity 

 at any place is denoted by g ; which is connected with I, the length 

 of the pendulum beating seconds in vacua, by the formula g = Tr-l. 



Latitude. 



0' 



45 0' 



48 9' 



48 50' 



51 29' 



51 32' 



52 30' 



53 21' 



53 29' 



54 36' 



Edinburgh 55 57' 



Aberdeen 57 9' 



Pole 90 0' 



Equator 



Latitude 45 



Munich 



Paris 



Greenwich . . , 

 Gottingen . . . 



Berlin 



Dublin 



Manchester , 

 Belfast .. 



